I have a 2002 4.0 tj with an awful noise. At first I thought hydraulic lifter but after more research it seems to be a problem within the engine itself. Not entirely sure. I was thinking of building 4.0 from the block up basically but I haven't been able to find the block alone, I don't want a full engine. More of a way to learn to build an engine myself. Anyone have a lead on a block or any other ideas that may come in handy for me?